Question

Are these annotations correct on the graph for velocity and acceleration?

Answer 1

Not quite.

A straight line on a x-t graph implies constant velocity... which tells you zero acc.

Answer 2

Determining acc is a little tougher:

If the slope of the x-t graph is getting steeper and rising, then acc. is positive.

If the slope of the x-t graph is getting flatter but still rising, then acc. is negative.


If the slope of the x-t graph is getting steeper and falling, then acc. is negative.

If the slope of the x-t graph is getting flatter but still falling, then acc. is positive.

Answer 3

On the last portion of the graph the slope is rising, but what do steeper/flatter mean?

Answer 4

Think of a steep hill vs flat ground.

Answer 5

The last part of the graph seems to be getting steeper

Answer 6

It is.

Answer 7

So its velocity and acceleration are positive? I understand the part now about constant velocity having 0 acceleration.

Answer 8

Yes. Velocity is positive when the graph is rising, and negative when the graph is falling.

Answer 9

Then the part from 10-18 seconds has a constant negative slope, so it has negative velocity and 0 acceleration?

Answer 10

For C, yes.

Answer 11

And for the second portion it's zero velocity and zero acceleration?
Thank you very much for your help!

Answer 12

Yes, a constant slope of zero on an x-t graph, as in a horizontal line, implies v = a = 0

A brief slope of zero on an x-t graph, like where a curve has a turning point, implies zero velocity but not zero acc.

Answer 13

Okay. Thanks!

Answer 14

Welcome.